Process and apparatus for insulating electric conduits.



O. THIBODEAU.

PROCESS AND APPARATUS FOR INSULATING ELEGTRIG GONDUITS.

APPLICATION FILED MAR. 26 3L 572B Patented Nov. 14, 1911.

CHARLES THIBODEAU, OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOR T0 AMERICANCIRCULAR LO0M COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION 01? MAINE.

PROCESS AND APPARATUS FOR INSULATING ELECTRIC CONDUITS.

Specification of Letters Patent.

Patented Nov. 142:, -1911..

Application filed March 26, 1910. Serial No. 551,723.

To all whom it may concern.

Be it known that I, CHARLES THIBODEAU, a citizenof the United States,residing at Cambridge, in the county of Middlesex and State ofMassachusetts, have invented new .layersnf porous textile fabric, thenpassing the same through a molten insulating and waterproofing compound,and finally drawing the tubing into a die which is keptat a temperaturesufficiently high to cause the said fabric to be saturated with saidcompound, and to firmly cement said fabric to j the framework of saidconduit. 25

My invention further consists in constructing an elongated trough or vathaving at the bottom thereof steam pipes for keeping at the propertemperature the insulating and waterproofing compound introducedthe1'ein, a guide roller being provided near the top of the trough andsecured to one of the side walls thereof for the purpose of dipping theconduit in said compound, combined with a die kept at a high temperatureand arranged to receive said conduit after ithas'been dipped in saidcompound. a

My invention further consists in constructingan oven consisting of atubular die of the same diameter as said conduit and,

provided with a beveled ingress opening, the wall of said die beinginclosed by asteam acket for the a purpose of subjecting the exterior ofsaid'conduit to a heat ofconsiderable temperature. j t .v r

My pinvention further consists .inlother improvements fully illustratedin the drawing and more specifically hereinafter point- I ed out andclaimed. a

Reference is hereby'made to in which similar numerals of. designation 1refer to similar parts throughout theseveral views. i

Figure 1 is a. p ewl ymy imnr'ovd. apparatus Showing the. g before the 1compound has been introduced therein, the

steam plpes at the bottom thereof, a portion of the conduit,the roller,and steam jacket. Fig. 2 is a side elevation, partly in section, of theview shown in Fig. 1, the trough, however, being shown filled with thecompound used for saturating the porous wrapping of the conduit. Fig. 3is an enlarged vertical section of the steam jacket and its connectionson line 33 of Fig. 1, looking in the direction of the arrows.

Referring to the drawing, the trough 4 is shown in the form of anelongated rectangular box supported by the legs 6, and is preferablyconstructed of metal or other material suitable for the purpose. Withinthe said trough and preferably resting uponthe ofI secure a rod 12 uponwhich is mounted the idler roll 11. Preferably one end of the said rodis threaded to engage with an opening in the side of said trough and tobe affixed and held in proper position by means of the nut 13. Thepurpose of said roll is to provide a means of positively dipping theconduit into the compound 14, (see Fig. 2). At the outer end of saidtrough is the guard or shield 15 to protect the conduit from injury'fromthe rough edge of said trough.

, Upon the opposite end of the trough 4,'is

mountedthe steam jacket 16, secured to the brackets 17, which are boltedto the upper edge of said trough. The said jacket is composed of thecylinder 18, ends 19 and 20,2.

die 22 fitting therein, an ingress pipe 24 and .an egress p pe 25. Theend 20'is formed with an opening 21 tapering'toward the interior'of saidjacket,'the better to'enable the taperedhead 28 of the die 22 toengagetherewith and form asteam tight joint,the

opposite endof said diepass'in through the opening 29 in the head 19 andeing threaded to engage with a nut 27, which serves to draw the head 28tightly within the opening 21, and which also serves to hermeticallyclose the 'ope'ning'29. Through the use of the tapered opening-'21, I amenabled to use different sizes of dies, which'though of varypreferablying diameters are formed with heads and shown) being employed toregulate the flow of said fluid. Preferably the trough 4 is constructedof such length that the conduit 23 passing therethrough shallbedeflected as slightly as possible out of the horizontal and straightline of its progress, the purpose being to keep the convolutions of thehelical frame of the preferred form of conduit used by the applicantclose together in order to revent the admission vof the compound 14 intothe interior of the conduit and the consequent obstruction of its bore.

The operation of my invention is as follows :The conduit 23 havingone ormore outer coverings or layers of textile fabrlc,

porous cotton cloth, and an interior framework supporting the same, isdrawn into the waterproofing and insulating compound 14:, under the rollII, the said compound bein heated to fluidlty by means of the steam pipe5. The conduit is then slowly introduced into the die 22, inclosed bythe steam jacket aforesaid, all surplus compound being removed by thehead 28. Preferablya temperature of approximately 300 degrees Fahrenheitis maintained'within the said acket, though the results of my inventionmay be produced by any tempera-. ture great enoughto cause the compoundcompletely to saturate the layers of cotton cloth and cause them toadhere to each other and to the framework aforesaid. The speed of thepassage'of the conduit through the die is preferably timed so thatduring said passage the said saturation and adhesion will be readilyaccomplished.

In the preferred form of my conduit, I employ as a basis or frame of thesame a flat strip of paper fiber helically Wound to form a tube, theconvolutions of said strip not being separated when the tube is held ina straight posit on. Around the said tube I preferably wind a thin tapeof porous cotton cloth, the edges of which overlap to a considerableextent, and over the layer of tape I weave or braid a seamless coveringof porous textile fabric, the construction of the conduit being of thesame general character as that described in Letters Patent No. 456,271to Herrick, dated July 21st, 1891, for flexible conduits, except thatthere are preferably no spaces left between the convolutions' of the siral framework. The said cloth and fabric are preferably so porous as topermit the compound when heated by the steam jacket to freely enter intotheir interstices as far as the fiber frame, the

convolutions of which being unseparated will not permit the saidcompound to enter the interior of said tube, though allowing saidcompound to work slightly into the line of separation between saidconvolutions. I am thus enabled to use as a waterproofing layer next tothe helical framework a cheap cotton tape, and at the same time to uniteand cement all parts together so as to give great strength andresiliency to the structure. VVhileI have described the use of saidporous covering or layers in connection with a helical or otherframework of a flexible electric conduit, I by no means desire so tolimit my invention to the use of the same, since it is obvious that myprocess and apparatus could be used to advantage in waterproofing orinsulating the exterior covering or coverings of any flexible electricconductor, conduit or other tubular structure with out departing fromthe spirit of my invena receptacle-containing waterproofingandinsulating compound and means for dipping the said conduit in saidcompound, combined with a die for scraping the surplus compound from theexterior of said conduit, said die being maintained at a temperaturesufliciently high'to saturate the said wrapping with said compound andto cause the same to adhere to said tubular support of said conduit: v

2. In an apparatus for waterproofing and insulating flexible electricconduits having a supporting tube and a porous outer covering, areceptacle containing waterproofing and insulating compound and meansfor dipping the said conduit in said compound, combined with anelongated die for scraping off the surplus compound from the exterior ofthe outer covering of said conduit, said die being inclosed in a steamjacket the temperature whereof is maintained at a degree suflicient tosaturate said outer covering with said compound and'to cause the same toadhere to the supportingtube of said conduit.

3. In an apparatus for waterproofing and insulating flexible electricconduits having a tubular support and a porous outer covering, areceptacle containing waterproofing and insulating compound and meansfor diping the said conduit in said compound, combined with an elongateddie for scraping off the surplus compound from the exterior of the outercovering of said conduit, said die 1 here to the said tubular support,andsaid die being detachably connected to said steam jacket and readilyremovable therefrom.

4. A steam jacket and die for saturating a porous covering of flexibleelectric conduits with waterproofing compound, consisting of anelongated metal box, one end whereof is formed with a tapered openingtherein, the other end having therein a circular opening, a tubular diehaving at one end a tapered head shaped to engage with said taperedopening, the other extremity of said die passing'through said circularopening and threaded to engage with a nut located on the exterior ofsaid jacket and hermetically sealing the same, combined with means forcausing steam to flow into and out of said jacket and to regulate thepassage of the same therethrough.

In testimony whereof I havehereunto set my hand in presence of twosubscribing witnesses, this 21st day of March 1910.

CHARLES THIBODEAU.

Witnesses:

HAROLD C. HAsKELL, K. M. SULLIVAN.

